A case of inherited glycosylphosphatidylinositol deficiency caused by PGAP3 variant with uniparental isodisomy on chromosome 17.

BACKGROUND: Inherited glycosylphosphatidylinositol (GPI) deficiency is an autosomal recessive disease and a set of syndromes caused by different genes involved in the biosynthesis of phosphatidylinositol characterized by severe cognitive disability, elevated serum alkaline phosphatase (ALP) levels, and distinct facial features. This report presents a patient with inherited GPI deficiency caused by a homozygous frameshift variant of PGAP3 due to uniparental isodisomy (UPiD) on chromosome 17. METHOD: Clinical characteristics of the patient were collected. Microarray analysis followed by adaptive sampling sequencing targeting chromosome 17 was used for the identification of variants. Sanger sequencing was used to confirm the variant in the target region. RESULTS: The patient was born at 38 weeks of gestation with a birthweight of 3893 g. He had a distinctive facial appearance with hypertelorism, wide nasal bridge, and cleft soft palate. Postnatal head magnetic resonance imaging revealed a Blake's pouch cyst. The serum ALP level was 940 IU/L at birth and increased to 1781 IU/L at 28 days of age. Microarray analysis revealed region of homozygosity in nearly the entire region of chromosome 17, leading to the diagnosis of UPiD. Adaptive sampling sequencing targeting chromosome 17 confirmed the homozygous variant NM_033419:c.778dupG (p.Val260Glyfs*14) in the PGAP3 gene, resulting in a diagnosis of inherited GPI deficiency. CONCLUSION: This is the first report of inherited GPI deficiency caused by UPiD. Inherited GPI deficiency must be considered in patients with unexplained hyperphosphatasemia.

Pharmacogenetic implementation for CYP2C19 and pharmacokinetics of voriconazole in children with malignancy or inborn errors of immunity.

BACKGROUND: Voriconazole pharmacokinetics (PK) are known to be affected by genetic polymorphisms of drug-metabolizing enzymes such as CYP2C19; however, such information is limited for the pediatric population. The primary aim of this study is to establish a voriconazole PK model incorporating CYP2C19 phenotypes in Japanese children with malignancy or inborn errors of immunity. METHODS: CYP2C19 genotypes were assessed by whole-genome genotyping and defined as follows: *17/*17: ultrarapid metabolizer (URM), *1/*17: rapid metabolizer (RM), *1/*1:normal metabolizer (NM), *1/*2, *1/*3, *2/*17:intermediate metabolizer (IM), and *2/*2, *2/*3, *3/*3: poor metabolizer (PM). Population PK analysis was performed. The voriconazole serum concentration profile was described by a two-compartment model with first-order absorption, mixed linear and nonlinear (Michaelis-Menten) elimination. RESULTS: Voriconazole concentration data were available from 60 patients with a median age of 5.3 years. The phenotypes predicted from CYP2C19 genotypes were RM in 1 (2 %), NM in 21 (35 %) patients, IM in 27 (45 %) patients, and PM in 11 (18 %) patients. Underlying diseases included 38 (63%) patients with hematological malignancy and 18 (30 %) patients with inborn errors of immunity. Among the CYP2C19 phenotypes, PM was predicted to show complete inhibition (the degree of Vmax inhibition [Vmax, inh] = 100 %; Vmax = 0). The estimated parameters of Vmax,inh were +0.8 higher in patients with gamma-glutamyl transpeptidase (γ-GTP) Grade 2 or higher and +2.7 higher when C-reactive protein (CRP) levels were 2.0 mg/dL or higher. CONCLUSION: CYP2C19 genetic polymorphisms, γ-GTP, and CRP affect Vmax,inh of voriconazole in children with malignancy or inborn errors of immunity.

Biologic and clinical analysis of childhood gamma delta T-ALL identifies LMO2/STAG2 rearrangements as extremely high-risk.

Acute lymphoblastic leukemia expressing the gamma delta T cell receptor (yo T-ALL) is a poorly understood disease. We studied 200 children with yo T-ALL from 13 clinical study groups to understand the clinical and genetic features of this disease. We found age and genetic drivers were significantly associated with outcome. yo T-ALL diagnosed in children under three years of age was extremely high-risk and enriched for genetic alterations that result in both LMO2 activation and STAG2 inactivation. Mechanistically, using patient samples and isogenic cell lines, we show that inactivation of STAG2 profoundly perturbs chromatin organization by altering enhancer-promoter looping, resulting in deregulation of gene expression associated with T-cell differentiation. High throughput drug screening identified a vulnerability in DNA repair pathways arising from STAG2 inactivation, which can be targeted by Poly(ADP-ribose) polymerase (PARP) inhibition. These data provide a diagnostic framework for classification and risk stratification of pediatric yo T-ALL.

Folate metabolism and risk of childhood acute lymphoblastic leukemia: a genetic pathway analysis from the Childhood Cancer and Leukemia International Consortium.

BACKGROUND: Prenatal folate supplementation has been consistently associated with a reduced risk of childhood lymphoblastic leukemia (ALL). Previous germline genetic studies examining the one carbon (folate) metabolism pathway were limited in sample size, scope, and population diversity, and led to inconclusive results. METHODS: We evaluated whether ~2,900 single nucleotide polymorphisms (SNPs) within 46 candidate genes involved in the folate metabolism pathway influence the risk of childhood ALL, using genome-wide data from nine case-control-studies in the Childhood Cancer and Leukemia International Consortium (n=9,058 cases including 4,510 children of European ancestry, 3,018 Latinx, and 1,406 Asians, and 92,364 controls). Each study followed a standardized protocol for quality control and imputation of genome-wide data, and summary statistics were meta-analyzed for all children combined and by major ancestry group using METAL software. RESULTS: None of the selected SNPs reached statistical significance, overall and for major ancestry groups (using adjusted Bonferroni p-value of 5x10-6 and less stringent p-value of 3.5x10-5 accounting for the number of "independent" SNPs). None of the 10 top (non-significant) SNPs and corresponding genes overlapped across ancestry groups. CONCLUSION: This large meta-analysis of original data does not reveal associations between many common genetic variants in the folate metabolism pathway and childhood ALL in various ancestry groups. IMPACT: Genetic variants in the folate pathway alone do not appear to substantially influence childhood ALL risk. Other mechanisms such as gene-folate interaction, DNA methylation or maternal genetic effects may explain the observed associations with self-reported prenatal folate intake.

Inhibition of the galactosyltransferase C1GALT1 reduces osteosarcoma cell proliferation by interfering with ERK signaling and cell cycle progression.

Novel therapeutic strategies are urgently required for osteosarcoma, given the early age at onset and persistently high mortality rate. Modern transcriptomics techniques can identify differentially expressed genes (DEGs) that may serve as biomarkers and therapeutic targets, so we screened for DEGs in osteosarcoma. We found that osteosarcoma cases could be divided into fair and poor survival groups based on gene expression profiles. Among the genes upregulated in the poor survival group, siRNA-mediated knockdown of the glycosylation-related gene C1GALT1 suppressed osteosarcoma cell proliferation in culture. Gene expression, phosphorylation, and glycome array analyses also demonstrated that C1GALT1 is required to maintain ERK signaling and cell cycle progression. Moreover, the C1GALT1 inhibitor itraconazole suppressed osteosarcoma cell proliferation in culture, while doxycycline-induced shRNA-mediated knockdown reduced xenograft osteosarcoma growth in mice. Elevated C1GALT1 expression is a potential early predictor of poor prognosis, while pharmacological inhibition may be a feasible treatment strategy for osteosarcoma.

Prediction of adverse cardiovascular events in children using artificial intelligence-based electrocardiogram.

BACKGROUND: Convolutional neural networks (CNNs) have emerged as a novel method for evaluating heart failure (HF) in adult electrocardiograms (ECGs). However, such CNNs are not applicable to pediatric HF, where abnormal anatomy of congenital heart defects plays an important role. ECG-based CNNs reflecting neurohormonal activation (NHA) may be a useful marker of pediatric HF. This study aimed to develop and validate an ECG-derived marker of pediatric HF that reflects the risk of future cardiovascular events. METHODS: Based on 21,378 ECGs from 8324 children, a CNN was trained using B-type natriuretic peptide (BNP) and the occurrence of major adverse cardiovascular events (MACEs). The output of the model, or the electrical heart failure indicator (EHFI), was compared with the BNP regarding its ability to predict MACEs in 813 ECGs from 295 children. RESULTS: EHFI achieved a better area under the curve than BNP in predicting MACEs within 180 days (0.826 versus 0.691, p = 0.03). On Cox univariable analyses, both EHFI and BNP were significantly associated with MACE (log10 EHFI: hazard ratio [HR] = 16.5, p < 0.005 and log10 BNP: HR = 4.4, p < 0.005). The time-dependent average precisions of EHFI in predicting MACEs were 32.4%-67.9% and 1.6-7.5-fold higher than those of BNP in the early period. Additionally, the MACE rate increased monotonically with EHFI, whereas the rate peaked at approximately 100 pg/mL of BNP and decreased in the higher range. CONCLUSIONS: ECG-derived CNN is a novel marker of HF with different prognostic potential from BNP. CNN-based ECG analysis may provide a new guide for assessing pediatric HF.

Case Report: Tuberous sclerosis complex-associated hemihypertrophy successfully treated with mTOR inhibitor sirolimus.

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder caused by a mutation in either of the two tumor suppressor genes, TSC1 and TSC2. Due to dysregulated activity of the mammalian target of rapamycin (mTOR) pathway, hamartomas or benign tumors frequently occur in many organs and are often treated with mTOR inhibitors. Hemihypertrophy is a rare complication of TSC. Although not being a tumor, progressive overgrowth of the affected limb may cause cosmetic and functional problems, for which the efficacy of mTOR inhibitors has not been reported previously. We herein report a case of TSC-associated hemihypertrophy. In this case, genetic studies revealed TSC1 loss of heterozygosity as the cause of hemihypertrophy. Clinically, pharmacological treatment with an mTOR inhibitor sirolimus successfully ameliorated cosmetic and functional problems with no intolerable adverse effects.

Ventriculosubgaleal shunt placement for hydrocephalus in osteogenesis imperfecta with novel compound heterozygous CRTAP variants.

Osteogenesis imperfecta is characterized by frequent fractures, bone deformities, and other systemic symptoms. Severe osteogenesis imperfecta may progress to hydrocephalus; however, treatment strategies for this complication remain unclear. Here, we describe severe osteogenesis imperfecta in an infant with symptomatic hydrocephalus treated with ventriculosubgaleal shunt placement. Targeted next-generation sequencing revealed novel compound heterozygous CRTAP variants, i.e., NM_006371.5, c.241 G > T, p.(Glu81*) and NM_006371.5, c.923-2_932del. We suggest that ventriculosubgaleal shunt placement is an effective and safe treatment for hydrocephalus in patients with severe osteogenesis imperfecta.

Congenital cytomegalovirus infection in a preterm infant with 22q11.2 deletion syndrome and immunological abnormalities.

The 22q11.2 deletion syndrome has many complications; one of them is immunodeficiency. However, the time of onset and the degree of immunodeficiency can vary. We report a case of a preterm infant with congenital cytomegalovirus infection complicated with 22q11.2 deletion syndrome and immunological abnormalities. Ultrasonography revealed pulmonary atresia, ventricular septal defect, major aortopulmonary collateral artery, and thymic hypoplasia. His serum chemistry tests on admission revealed immunoglobulin G, A, and M levels of 1,547 mg/dL, 70 mg/dL, and 274 mg/dL, respectively. A surface antigen analysis of the peripheral lymphocytes using flow cytometry revealed the following: relatively low CD4-positive T-cell levels (18.1%; 1,767/µL), very high CD8-positive T-cell levels (58.9%; 5,751/µL), and CD4/CD8 ratio of 0.31. The level of T-cell receptor excision circles was relatively low at 17.5 copies/µL. After birth, the CD8-positive T-cell level began to gradually decrease, whereas the CD4/CD8 ratio began to increase. Thrombocytopenia, neutropenia, and skin petechiae were observed on admission. However, the condition improved. Treatment for congenital cytomegalovirus infection was not provided due to the absence of viremia. Unfortunately, the patient died suddenly on the 158th day of life, and the cause of death was unknown. To the best of our knowledge, no association between 22q11 deletion syndrome and cCMV has been described in the recent medical literature. According to the calculation, around one newborn infant who have both 22q11 deletion syndrome and cCMV infection will be born each year in Japan. Healthcare providers should pay more attention to this medical situation in the future.

Post-renal Biopsy Retroperitoneal Haematoma Accompanied by Decreased Coagulation Factor XIII Levels in Immunoglobulin A Nephropathy.

Post-biopsy bleeding is the primary complication of renal biopsy. Retroperitoneal haematoma is a rare but severe bleeding complication; it commonly occurs among patients who have risk factors or vascular lesions. The bleeding risks in patients with immunoglobulin A (IgA) nephropathy (IgAN) have been discussed in the literature, but clinical data are lacking. Here, we report a case of a post-biopsy retroperitoneal haematoma accompanied by decreased coagulation factor XIII (FXIII) in a patient with IgAN. A 14-year-old male patient with haematuria and proteinuria but no bleeding or family history of bleeding underwent pre-renal biopsy evaluation that showed no coagulation abnormalities. He underwent percutaneous renal biopsy, and the histopathological diagnosis was IgAN. Five days after the biopsy, he presented with delayed bleeding from a retroperitoneal haematoma. During the workup for undiagnosed haemorrhagic diatheses, a mildly decreased FXIII level was discovered. This result suggested the possibility of bleeding complications associated with decreased FXIII. Some bleeding diatheses, including FXIII deficiency, cannot be evaluated in routine pre-biopsy coagulation tests. Mild FXIII deficiency can increase the risk of post-biopsy bleeding complications. Therefore, physicians should consider unevaluated haemorrhagic diatheses when a patient presents with major bleeding complications or delayed bleeding following renal biopsy without any known risk factors or vascular lesions.

Scoring system for diagnosis and pretreatment risk assessment of neuroblastoma using urinary biomarker combinations.

The urinary catecholamine metabolites, homovanillic acid (HVA) and vanillylmandelic acid (VMA), are used for the adjunctive diagnosis of neuroblastomas. We aimed to develop a scoring system for the diagnosis and pretreatment risk assessment of neuroblastoma, incorporating age and other urinary catecholamine metabolite combinations. Urine samples from 227 controls (227 samples) and 68 patients with neuroblastoma (228 samples) were evaluated. First, the catecholamine metabolites vanillactic acid (VLA) and 3-methoxytyramine sulfate (MTS) were identified as urinary marker candidates through comprehensive analysis using liquid chromatography-mass spectrometry. The concentrations of these marker candidates and conventional markers were then compared among controls, patients, and numerous risk groups to develop a scoring system. Participants were classified into four groups: control, low risk, intermediate risk, and high risk, and the proportional odds model was fitted using the L2-penalized maximum likelihood method, incorporating age on a monthly scale for adjustment. This scoring model using the novel urine catecholamine metabolite combinations, VLA and MTS, had greater area under the curve values than the model using HVA and VMA for diagnosis (0.978 vs. 0.964), pretreatment risk assessment (low and intermediate risk vs. high risk: 0.866 vs. 0.724; low risk vs. intermediate and high risk: 0.871 vs. 0.680), and prognostic factors (MYCN status: 0.741 vs. 0.369, histology: 0.932 vs. 0.747). The new system also had greater accuracy in detecting missing high-risk neuroblastomas, and in predicting the pretreatment risk at the time of screening. The new scoring system employing VLA and MTS has the potential to replace the conventional adjunctive diagnostic method using HVA and VMA.

Treatments and outcomes of neonatal disseminated intravascular coagulation with and without neonatal asphyxia: A retrospective study using nationwide data in Japan.

BACKGROUND: Although neonatal disseminated intravascular coagulation (DIC) is associated with high mortality and severe complications, few studies have reported its clinical course. We aimed to describe the characteristics, treatments, and outcomes of neonatal DIC by using a national inpatient database. METHODS: Using the Japanese Diagnosis Procedure Combination database, we identified 5533 patients with neonatal DIC who were admitted to neonatal intensive care units between July 2010 and March 2020. We categorized the patients into those with asphyxia (n = 2911) and those without asphyxia (n = 2622). We investigated the patient characteristics, treatments, and outcomes. We further categorized neonates with asphyxia according to its severity. RESULTS: The gestational age of neonates with asphyxia was significantly lower than that of neonates without asphyxia (P < 0.001). Antithrombin was most commonly used for DIC (40%). Neonates with asphyxia were more likely to receive antithrombin (43% vs. 38%; P < 0.001), recombinant human soluble thrombomodulin (28% vs. 20%; P < 0.001), and fresh frozen plasma transfusion (68% vs. 51%; P < 0.001) than those without asphyxia. Neonates with asphyxia had higher in-hospital mortality (17% vs. 10%; P < 0.001), severe bleeding (11% vs. 6.8%; P < 0.001), and hospitalization costs than those without asphyxia. Additionally, neonates with severe asphyxia were more likely to receive several DIC therapies (such as recombinant human soluble thrombomodulin [30% vs. 24%]) and had higher in-hospital mortality (19% vs. 11%) and hospitalization costs than those with mild asphyxia. CONCLUSIONS: In this large retrospective study of neonatal DIC, patients with asphyxia received several treatments and demonstrated unfavorable outcomes when compared to those without asphyxia.

Challenges to Widespread Use of Fertility Preservation Facilities for Pediatric Cancer Patients in Japan.

Purpose: Although fertility preservation for pediatric cancer patients is becoming more widespread in Japan, some facilities do not provide sufficient information regarding fertility. This study aimed to elucidate the problems pertaining to the lack of information about fertility among patients. Methods: Based on a 2020 survey, seminars addressing fertility preservation were held from the Designated Pediatric Cancer Care Hospitals in each of the seven blocks in Japan to their partner hospital (pediatric cancer hospitals). The seminar consisted of lectures and group discussions, and a questionnaire was also administered after each seminar. Results: In the group discussions, a lack of explanations to patients and explanatory materials for children were cited as issues by many facilities. The survey results revealed a lack of material explaining fertility preservation and a lack of knowledge among health care providers. There were also many requests to use the patient explanation videos presented at the seminar. Conclusion: The results indicate that further education for health care providers by seminar and other sources and enhancement of explanatory materials are important for fertility preservation in pediatric cancer hospitals in Japan.

Melting temperature mapping method in children: Rapid identification of pathogenic microbes.

INTRODUCTION: The melting temperature (Tm) mapping method (TM) identifies bacterial species by intrinsic patterns of Tm values in the 16S ribosomal RNA gene (16S rDNA) extracted directly from whole blood. We examined potential clinical application of TM in children with bloodstream infection (BSI). METHODS: This was a prospective observational study at a children's hospital in Japan from 2018 to 2021. In patients with diagnosed or suspected BSI, we investigated the match rates of pathogenic bacteria identified by TM and blood culture (BC), the inspection time to identification of TM, and the amount of bacterial DNA in blood samples. RESULTS: The median age of 81 patients (93 samples) was 3.6 years. Of 23 samples identified by TM, 11 samples matched the bacterial species with BC (positive-match rate, 48 %). Of 64 TM-negative samples, 62 samples were negative for BC (negative-match rate, 97 %). Six samples, including one containing two pathogenic bacterial species, were not suitable for TM identification. In total, the matched samples were 73 of 93 samples (match rate, 78 %). There were seven samples identified by TM in BC-negative samples from blood collected after antibiotic therapy. Interestingly, the bacteria were matched with BC before antibiotic administration. These TM samples contained as many 16S rDNA copies as the BC-positive samples. The median inspection time to identification using TM was 4.7 h. CONCLUSIONS: In children with BSI, TM had high negative-match rates with BC, the potential to identify the pathogenic bacteria even in patients on antibiotic therapy, and more rapid identification compared to BC. REGISTERING CLINICAL TRIALS: UMIN000041359https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000047220.

Physiologically based pharmacokinetic (PBPK) model that describes enhanced FcRn-dependent distribution of monoclonal antibodies (mAbs) by pI-engineering in mice.

We previously reported that monoclonal antibodies (mAbs) with a high isoelectric point (pI) value tended to exhibit fast plasma clearance (CL) and large steady-state volume of distribution (Vdss) in mice. However, the positive correlation between pI, CL, and Vdss cannot be described by the reported physiologically based pharmacokinetic (PBPK) models, in which FcRn-mediated transcytosis of mAbs is set to be minimal compared to convection-mediated transport. To address this issue, physiological parameters (lymph flow rate, reflection coefficient, endothelial uptake clearance, and FcRn concentration) were optimized based on the pharmacokinetic profiles of mAbs with various pI values in wild type and FcRn-deficient (beta-2-microglobulin knockout [KO]) mice. Simulations using the PBPK model developed in this study showed a positive correlation between pI, CL and Vdss observed in wild-type mice. Therefore, this model successfully characterized our hypothetical mechanism that an electrostatic positive interaction between mAbs and the endothelial membrane enhances FcRn-mediated transcytosis of mAbs, resulting in large Vdss. We sought to determine the right contribution of the two pathways of antibody distribution to the interstitial space and established a new model that could effectively capture the effect of pI on FcRn-mediated distribution of mAbs in the body.